The present invention relates to latch assemblies and latch arrangements in particular for use on car doors.
Manufacturers of cars have been endeavoring to reduced in-car noise, and in particular wind induced in-car noise. One way of achieving this is to provide for door seals which, when a door is in the fully closed position exert a higher force between the door and adjacent door surround.
However, the problem with such arrangement is that it becomes increasingly difficult to unlatch the door since those components that secure the door in a latched position e.g. a latch bolt (such as a claw) and a pawl, are under increased load resulting in higher friction. In particular where the door is to be opened by a power actuator, larger and more expensive power actuators are required to be specified in order to be ensure correct unlatching of the door.
An object of the present invention is to provide a latch assembly and a latch arrangement which can be released more easily than known latch assemblies and latch arrangements.
Thus according to the present invention there is provided a latch assembly including a latch bolt moveable between a closed position at which it is capable of retaining a striker and an open position at which it is capable of releasing a striker, the latch assembly further including a pawl moveable between a retaining position at which it is capable of retaining the latch bolt in at least it closed position and a released position at which the latch bolt is free to move between its open and closed position, in which the pawl is rotatably mounted via a rotating element bearing.
The applicant is the first to realize that significant friction forces are developed at the pivot point of a pawl and therefore these forces can be reduced by installing a rotating element bearing at this position.
Preferably the rotating element bearing inner race is integral with the pawl pivot pin.
Advantageously such an arrangement means that a separate outer race and or inner race need not be provided. The applicant is the first to realize that the material that the pawl and pawl pivot pin are made from is of sufficient quality to act as bearing race material. In particular the structural integrity of the pawl and pawl pivot pin are important when the vehicle is involved in a collision, in as much as their failure could result in the door opening thus jeopardizing the safety of the car occupants and it is for this reason that they tend to be manufactured from high grade steel.
According to a further aspect of the present invention there is provided a latch assembly including a first release lever being pivotable about a first axis and having plurality of first gear teeth and a second release lever being pivotable about second axis and having a plurality of second gear teeth for co-operation with the plurality of first gear teeth, operation of the first release lever causing the second release lever to unlatch the latch in which the first axis is not parallel to the second axis.
Thus where it is necessary for the forces acting via a transmission path to turn through an angle this aspect of the present invention provides for a significant reduction in friction forces.